Many prior arc welders have relied on heat exchange systems to dissipate and remove heat from the head of the welding apparatus. These heat exchange systems generally utilize water, which is pumped around the heat generating portion of the welding apparatus, and where the water is then sent to a cooling station, generally comprising a set of coils and a means to move air across the surface of said coils.
Water and other liquids require a water tight barrier between the water and other parts of the apparatus. Since arc welders themselves rely on electricity that has sufficient voltage to cause an arc, any introduction of water against the parts of the apparatus that are used to conduct electrical current, can cause shock to the operator, who is generally holding onto the apparatus. In addition, water circulating systems are high maintenance systems, since the liquid must be changed frequently and the used coolant must be disposed of according to any required environmental protection agency regulations.
Several other methods of cooling welding assemblies, involving the use of air cooling techniques, have been tried with varying degrees of results. The methods of the air cooling, provides a unique problem with welding guns, since an inert gas shield must still be provided during the welding process. Interruption of the flow of the inert gas, around the spot or point being welded, can cause poor quality welding.
This invention is an improvement on U.S. Pat. No. 5,248,868 entitled "Welding Gun" (Corrected from "Melding Gun"), issued on Sep. 28, 1993. In that invention, the use of rapidly moving air was shown, in which the air evacuated the head or front portion of the welding apparatus. The venting of the air, since it is so near the welding head, could cause problems and interrupt the welding process in the tungsten inert gas welding process. The present invention avoids the air circulation problems, and maximizes the cooling ability of the apparatus.
This invention is also on improvement on U.S. Pat. No. 4,297,561 entitled "Semi-automatic Welding Gun", issued Oct. 27, 1981. U.S. Pat. No. 4,297,561 describes an air cooled semi automatic welding gun assembly as contrasted with the present invention of an air cooled welding gun assembly, in which air is returned inside the outer jacket, adjacent to the copper cables, using the copper cables as a means; to further carry out excess heat, and venting the air at the rear connector block.
This invention is also an improvement on U.S. Pat. No. 4,864,099 entitled "Water Cooled Semi-Automatic Welding Gun", issued Sep. 5, 1989. U.S. Pat. No. 4,864,099 describes a water cooled welding gun assembly as further contrasted with the air cooled welding gun assembly described and claimed herein.